I did a search before posting but couldnt find an answer so please forgive the question.

I have a 2 year old SSD as my OS HDD and a month ago I saw the Lifetime Writes number was 600GB and opened today is down to Lifetime writes: 508.22GB

I've read the in-built help guide, site FAQ and forum and can't find an answer to what the Overview -> Lifetime Writes means for an SSD. Does it mean my SSD can only have another 500GBof data written to it before it fails and I should panic or...? If it could be confirmed if Lifetime Writes is a countdown to expiration plesae. Estimated remaining lifetime: more than 1000 days also shows.

Generally the lifetime writes recorded in the SSD, Hard Disk Sentinel reads and displays that value.It should never decrease, as all writes only increase the total amount of data written.

Please contact the manufacturer of the SSD (Samsung in this case) as they may give information what could cause that the recorded value decreased (which should never happen).

If you use Report menu -> Send test report to developer option, I can examine the complete status of the SSD any time (including the self-monitoring data). Generally the S.M.A.R.T. page contains the details, including the total amount of data written. If you select that attribute, on the bottom it is possible to examine how it changes with time.